Automatic control device



Sept. 11, 1928. 1,683,856 T. F. BAIL Y Filed Aug. 20, 1926 1 2Sheets-Sheet Sept. 11, 1928. wmsss T. F. BAILY AUTOMATIC CONTROL DEVICEFiled Aug. 20, 192s 2 Sheets-$heet 2 ilk/neuter (krona e4 4 PatentedSept. 11, 1928 UNITED sures PATENT OFFIQE.

THADDEUS F. BAILY, F ALLIANCE, OHIO.

AU'romAirIc con'rnor. nnvrcn.

Application filed August 20, 1926. Serial No. 130,522.

The invention relates to a device for regulating the current from atransformer to an electric furnace or the like; and the object of theimprovement is to provide means for automatically breaking the hightension circuit to the transformer before the regulating mechanism isput into operation, thus preventing damage to the transformer.

An embodiment of the invention is illusw trated in the accompanyingdrawings, in

which Figure 1 is a perspective view of the improved controlling device,and

Fig. 2, a diagrammatic view of the same.

Similar numerals of reference indicate corresponding .parts throughoutthe drawings.

The transformer is shown at 1,'the primary winding thereof being tappedat a plurality of points as indicated at 2. One wire 3 of the m hightension circuit leads to one side of the primary winding of thetransformer and the other wire 4 thereof leads to a movable contactingblade 5 arranged to contact with each of the contact points 6 upon thetaps 2.

The wires 7 lead from the secondary winding of the transformer to thefurnace or the like which is to be operated. The movable blade 5 isfixcdupon a rotatable shaft 8 arranged to be rotated or oscillated in anysuitan able manner, as by the worm gear 9 fixed upon the shaft andengaged by the worm 10 upon the shaft of the reversing motor 11.

The wire 12 leads from the reversin motor to one wire 13 of a 110 voltcircuit, eing also connected to a fixed contact point 14. A

similar contact point 14 is spaced from the point 14 andconne cted bythe wire 15 to the reversing motor. The third wire 16 leads from thereversing motor to a switch point 17, w opposite to the point 14. Acontact point 17 spaced from the point 17 is connected to the point 14as by the wire 18.

A movable switch blade 19 is arranged to be moved into contact with thecontact points 45 17 and 17 or 14 and 14 alternately, and is fixed tothe double core 20, arranged to be alternately actuated by the solenoids21 and 22, which are connected to the wires 23 and 24 respectivelyleading to a suitable circuit mak- 5n ing and breaking device, such as acontacting pyrometer of any usual and well-known construction arrangedto be actuated by a thermocouple in the furnace, in the usual manner.

A wire 25 is connected to both solenoids 55 and leads to a magnet 26which is also connected, as by the wire 27 to the contacting pyrometeror circuit making and breaking device to which the solenoids 21 and 22are connected.

The armature 28 is arranged to be normally held away from the magnet,'asby a spring 29, and is provided with the latch portion 30 for engagementwith the lever switch 31, pivoted as at 32 and connected to the wire 33forming the other side of the 110 volt circuit.

The switch lever 31 is arranged to alternately contact with the fixedcontact points 34 and 35, the point 34 being connected, as by the wire36, with the wire 16, and the point 35 being connected, as by the wire37, with the solenoid 38.

The solenoid 38 is also connected to the wire 13, of the 110 voltcircuit. The core 39 of this solenoid is provided with a switch blade 40arranged to engage the contact points 41,

sion circuit. y

A roller 42 is carried by the switch lever 31 and arranged to ride uponthe periphery of the cam wheel 43, which is fixed upon the shaft 8.

In the operation of the device, the high tension circuit is normallyclosed through the solenoid switch 40; the switch 19 is in the positionshown in Fig. 2, breaking the circuit to the motor 11, and the cam wheelis in the position shown in said figure, the roller 42 being oppositeone of the recesses 44 therein, and holding the switch lever 31 inengagement with the contact point 35, and holding the contacting blade 5in contact with one-0f the points 6.

The rising or falling of the temperature in in the wire 3, to make andbreak the high tenv the furnace will operate the pyrometer to energizeeither the solenoid 21 or 22, as the case may be. When the solenoid 21is energized the switch 19 will be moved into contact with the points1717.

At the same time the magnet 26 will be energized, pulling the latch 28out of engagement with the switch lever 31, and permitting the spring 45to throw the switch 31 into engagement with the contact point 34,breaking the 110 volt circuit to the solenoid switch 3840 and openingthe high tension circuit.

The circuit to the reversing motor 11 is then closed through the wires13, 12, 16, and 36, switch lever 31 and wire 33, operating the motor inone direction and changing the position of the contacting arm 5, throughthe the switch lever 31 and holding it in contact with the point 35,while the switch 19 will again assume the normal position, shown in Fig.2. v

The 110 volt circuit, to the switch solenoid 38, will again becompleted, energizing this solenoid and closing the switch 40,completing the high tension circuit to the transformer; and the furnacewill again function normally until the temperature rises or fallssufficiently to operate the pyrometer again.

Assuming that the next operation of the pyrometer energizes the solenoid22, the

switch 19 will be closed through the contacts 14: and 14. In this eventthe current from the 110 volt circuit passes from wire 13 through wire12, switch 19, and wire 15 to the motor, then through wires 16 and 36,

switch 31 and wire 33.

v The motor is thus operated in reversed di rection moving the blade 5in the opposite direction while the operation of the other parts is thesame as above described.

I claim: I

1. In combination with a transformer, a high tension circuit leading tothe transformer and means for varying the voltage from the transformer,a control device for operating said voltage varying means and means insaid control device to break the high tension circuit before the voltagevarying means is operated.

2. In combination with a transformer, a

high tension circuit leading to the transa furnace connected to thetransformer,

voltage former, and means for varying the from the transformer to thefurnace, a control device operated by the temperature of the furnace foroperating said voltage varying means, and means in said control deviceto break the high tension circuit before the voltage varying means isoperated.

3. In combination with a transformer and a high tension circuit leadingto the transformer, a control device including a movable contactingblade for varying the voltage from the transformer, a switch in the hightension circuit and means foropening said switch before saidcontactingblade is moved.

4. In combination with a transformer and a high tension circuit leadingto the trans former, a control device including a movable contactingblade for varying the voltage from the trans-former, a motor foroperating the" contacting blade, a switch in the high tension circuitand means for opening said switch be fore said motor is operated.

5. In combination with a transformer, a high tension circuit leading tothe transformer and means for varying the voltage from the transformer,a control device for operating said voltage varying means and means insaid control device to break the high tension circuit before the voltage"varying means is operated, and means controlled by the operation of thevoltage varying means for closing the high tension circuit after thevoltage varying means is operated.

6. In combination with a transformer, a high tension circuit leading tothe transformer, a furnace connected to the transformer, and means forvarying the voltage from the transformer to the furnace, a controldevice operated by the temperature of the furnace for operating saidvoltage varying means, and means in said control device to break thehigh tension circuit before the voltage varying means is operated, andmeans controlled by the operation of the voltage' varying means forclosing the high tension circuit after the voltage varying means isoperated.

7 In combination with a transformer and a high tension circuit leadingto the transformer, a control device including a movable contactingblade for varying the voltagefrom the transformer, a switch in the hightension circuit and means for opening said switch before said contactingblade is moved, v

and means controlled by the movement of said contacting blade forclosing switch after the contacting blade is moved.

8. In combination with a'tr a high tension circuit leading to thetransformer, a control device including a movable contacting blade forvarying the voltage from the transformer, a motor ,for operating thecontacting blade, a switch in the high tension circuit and means foropenin said switch before said motor is operated, and means controlledby the operation of the motor for closing said switch after the motor isoperated.

In testimony that I claim the above, I have hereunto subscribed my name.

THADDEUS F. BAILY.

ansformer and

